Yellow tang rubbing on rocks

My yellow tang is rubbing on the rocks in my tank. There is no sign of ich...... All of the other fish seem fine also. He's rubbing so much it looks like there is redish irritation spots on his side. Has any one seen this?

 

Rubbing on sand and rocks is called flashing.

What are you feeding?
How long have you had the fish?

I do see the red area by the base of the tail?

 

alot of times ich does not become very visible until it is very bad. often times at night it also becomes more pronounced.

 

Thats what I would have said also, they will rub also if they have ich in trying to remove them.

 

There is a redish area in front of the white spot near his back tail. I feed him algae on a clip 3 to 4 times a week, hikari mega marine algae, hikari spirulina brine shrimp

 

I was going to suggest ich too. Might think about putting him in the QT and treating just in case? Even if it isn't, that red rash could develop an ich or bacterial infection.

Thoughts on that?

 

Would it be possible the tang is trying to take over the whole tank flashing on all the rocks causing the red spots?

 

Its possible Yellow Tangs can be highly aggresive. What size tank is this?What is the stocking list? Also removing the fish will do absolutely no good. If the fish is infected with Ich it is in your system and unless you remove all your fish it is not worth the trouble IMO. Also Ich goes through 4 different stages in its life cycle. The only time it is visible is in the TROPHONT STAGE which is the last stage before it becomes free swimming. As long as the fish remains eating it should be able to combat the parasite on its own.This may or may not be the reason its flashing though.

 

It's a 75g with 160 to 170lbs of live rock. I have 4 green chromis, 2 zebra dartfish, 2 fire gobys, 2 ocellaris clowns, green mandarin, blue damsel, yellow eye kole tang, yellow wrasse, banggai cardinal. He doesn't seem to chase or fight with any fish. Some times backs up to them an rubbing on rocks an/or flashing. He eats great lots of algae, vitamin enriched frozen fish food. None of the other fish seem to be rubbing or have any signs of illness.

Nitrates-0
Nitrites-0
Ammonia-0
PH- 7.70 (may need to calibrate ph probe)

 

15?Wow that is alot of fish for a 75 gallon. IMO one small Tang would be pushing it. Aggresion is not always easily observed and can be as simple as posturing/flashing and or vocalization threats. I would seriously consider rehoming the Yellow. Its aggresion may increase as it gets bigger especially in a small tank with alot of other fish.The flashing could be from the Tang trying to show territorial dominance or it could be the first signs of Ich.
P.S. The fact that the Tang backs up to other fish makes sense as they have a razor sharp appendage at the base of the tail used for slashing at other fish.This is a sign of aggresion.